Differences between cysteine and homocysteine in the induction of deoxyribose degradation and DNA damage
Differences between cysteine and homocysteine in the induction of deoxyribose degradation and DNA damage
复制标题
DOI：
10.1016/s0891-5849(00)00480-9
复制
发表时间：
2001-02-15
影响因子：
7.4
通讯作者：
Sáez, GT
中科院分区：
文献类型：
--
作者：
Muñiz, P;Sáez, P;Sáez, GT
已经检查了两种天然存在的硫醇（例如半胱氨酸和同型半胱氨酸）诱导脱氧核糖降解和 DNA 的作用。损害。已将铜 (II) 离子添加到孵育混合物中，并进行耗氧量测量，以便将观察到的破坏效应与金属催化硫醇氧化的速率关联起来。抗坏血酸加铜已被用作活性氧导致的脱氧核糖和 DNA 氧化的阳性对照。半胱氨酸或同型半胱氨酸在铜离子存在下会诱导脱氧核糖的降解和 8-羟基-2'-脱氧鸟苷 (8-OHdG) 的产生，尽管在所测试的两种硫醇之间观察到重要差异，同型半胱氨酸的反应性低于半胱氨酸。 DNA 裂解在铜 (II) 离子存在下由半胱氨酸诱导，但同型半胱氨酸则不诱导。过氧化氢酶和硫脲，但不是超氧化物歧化酶 (SOD)，被证明可以抑制半胱氨酸对脱氧核糖或 DNA 的破坏作用，表明 H2O2 和 (OH)-O-。自由基是造成所观察到的诱导损伤的原因。结果表明，所测试的两种硫醇对脱氧核糖和DNA损伤的破坏作用存在差异。将讨论病理生理学的重要性。 (C) 2001 爱思唯尔科学公司。
The effect of two naturally occurring thiols, such as cysteine and homocysteine, has been examined for their ability to induce deoxyribose degradation and DNA. damage. Copper(II) ions have been added to incubation mixtures and oxygen consumption measurements have been performed in order to correlate the observed damaging effects with the rate of metal catalyzed thiol oxidation. Ascorbic acid plus copper has been used as a positive control of deoxyribose and DNA oxidation due to reactive oxygen species. Cysteine or homocysteine in the presence of copper ions induce the degradation of deoxyribose and the yield of 8-hydroxy-2'-deoxyguanosine (8-OHdG), although important differences are observed between the two thiols tested, homocysteine being less reactive than cysteine. DNA cleavage is induced by cysteine in the presence of copper(II) ions but not by homocysteine. Catalase and thiourea, but not superoxide dismutase (SOD), were shown to inhibit the damaging effects of cysteine on deoxyribose or DNA suggesting that H2O2 and (OH)-O-. radicals are responsible for the observed induced damage. The results indicate that there are differences between the damaging effects of the two thiols tested towards deoxyribose and DNA damage. The pathophysiological importance will be discussed. (C) 2001 Elsevier Science Inc.